Polyurethane dispersion, gas barrier coating material, and laminate

Abstract

To provide a polyurethane dispersion and a gas barrier coating material capable of forming a polyurethane layer having excellent gas barrier properties, heat resistance, and storage stability, and further to provide a laminate including the polyurethane layer.SOLUTION: A polyurethane dispersion is an aqueous dispersion of a polyurethane resin. The polyurethane resin is a reaction product of an isocyanate group-terminated prepolymer and a chain extender. The isocyanate group-terminated prepolymer includes a reaction product of a polyisocyanate component containing a xylylene diisocyanate, and an active hydrogen group-containing component containing a short-chain diol having 2 to 6 carbon atoms and an active hydrogen group-containing compound containing a hydrophilic group. The chain extender includes an ethylenediamine. The proportion of the ethylenediamine is 25 mol% or more relative to the total amount of the chain extender.SELECTED DRAWING: Figure 1

Description

Technical Field

[0001] The present invention relates to a polyurethane dispersion, a gas barrier coating material, and a laminate.

Background Art

[0002] Conventionally, it has been known to impart gas barrier properties to a substrate by forming a resin layer containing a polyurethane resin (hereinafter, a polyurethane layer) on the surface of the substrate.

[0003] As a method for producing a polyurethane resin, the following has been proposed. First, a carboxylic acid group-containing polyurethane prepolymer is synthesized by reacting hydrogenated XDI, dimethylolpropionic acid, and ethylene glycol. Next, the carboxylic acid group is neutralized with triethylamine. Then, the carboxylic acid group-containing polyurethane prepolymer is subjected to a chain extension reaction with ethylenediamine. Also, a gas barrier film obtained by laminating a polyurethane resin on the surface of a biaxially stretched polypropylene film has been proposed (see, for example, Patent Document 1 (Production Example 8)).

Prior Art Documents

Patent Documents

[0004]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0005] On the other hand, as the polyurethane layer, heat resistance may be further required. However, the above polyurethane resin has insufficient heat resistance. Also, excellent storage stability is required for the polyurethane resin.

[0006] The present invention relates to a polyurethane dispersion capable of forming a polyurethane layer excellent in gas barrier properties, heat resistance, and storage stability, a gas barrier coating material, and a laminate provided with a polyurethane layer.

Means for Solving the Problems

[0007] The present invention [1] is a polyurethane dispersion which is an aqueous dispersion of a polyurethane resin, wherein the polyurethane resin is a reaction product of an isocyanate group-terminated prepolymer and a chain extender, the isocyanate group-terminated prepolymer includes a polyisocyanate component containing xylylene diisocyanate, a short-chain diol having 2 to 6 carbon atoms, and an active hydrogen group-containing component including an active hydrogen group-containing compound having a hydrophilic group, the chain extender includes ethylenediamine, and the proportion of ethylenediamine in the total amount of the chain extender is 25 mol% or more.

[0008] The present invention [2] includes the polyurethane dispersion according to [1] above, wherein the active hydrogen group-containing component further includes an alcohol having a valence of 3 or more, and the proportion of the alcohol having a valence of 3 or more in the total amount of the active hydrogen group-containing component is 1 mol% or more and 15 mol% or less.

[0009] The present invention [3] includes the polyurethane dispersion according to [1] or [2] above, wherein the polyisocyanate component further includes methylene bis(cyclohexyl isocyanate), and the content ratio of methylene bis(cyclohexyl isocyanate) in the total amount of the polyisocyanate component is 1 mol% or more and 30 mol% or less.

[0010] The present invention [4] includes the polyurethane dispersion according to any one of [1] to [3] above, wherein the coefficient of thermal expansion of the polyurethane resin is 2000×10 -6 K -1 or less.

[0011] The present invention [5] further includes the polyurethane dispersion according to any one of [1] to [4] above, which contains at least one selected from the group consisting of an epoxy silane, a water-dispersible polyisocyanate, and a carbodiimide compound.

[0012] The present invention [6] includes the polyurethane dispersion according to [5] above, wherein the content ratio of the carbodiimide group in the carbodiimide compound is 0.3 mol or more and 3.0 mol or less per 1 mol of the carboxy group in the polyurethane resin.

[0013] The present invention [7] includes a gas barrier coating material containing the polyurethane dispersion according to any one of [1] to [6] above.

[0014] The present invention [8] includes a laminate including a substrate and a polyurethane layer disposed on the surface of the substrate, wherein the polyurethane layer is a dried product of the gas barrier coating material according to [7] above.

Effects of the Invention

[0015] In the polyurethane dispersion of the present invention, the polyisocyanate component contains xylylene diisocyanate, and the chain extender contains a predetermined ratio of ethylenediamine.

[0016] Therefore, the polyurethane dispersion of the present invention contains a polyurethane resin excellent in gas barrier properties, heat resistance, and storage stability.

[0017] As a result, the polyurethane dispersion and the gas barrier coating material of the present invention can form a polyurethane layer excellent in gas barrier properties, heat resistance, and storage stability.

[0018] In the laminate of the present invention, the polyurethane layer is a dried product of the gas barrier coating material. Therefore, the laminate of the present invention is excellent in gas barrier properties and heat resistance.

Brief Description of the Drawings

[0019]

Figure 1

Figure 2

Figure 3

Mode for Carrying Out the Invention

[0020] The polyurethane dispersion of the present invention is an aqueous dispersion of a polyurethane resin.

[0021] Examples of the polyurethane resin include a gas barrier polyurethane resin. Note that gas barrier properties refer to the property of reducing the oxygen transmission rate.

[0022] The gas barrier polyurethane resin contains a reaction product obtained by reacting at least a polyisocyanate component and an active hydrogen group-containing component.

[0023] More specifically, the gas barrier polyurethane resin is obtained by reacting an isocyanate group-terminated prepolymer with a chain extender. The isocyanate group-terminated prepolymer is obtained by reacting a polyisocyanate component with an active hydrogen group-containing component. That is, the isocyanate group-terminated prepolymer is a primary reaction product of a polyisocyanate component and an active hydrogen group-containing component. The gas barrier polyurethane resin is a secondary reaction product of an isocyanate group-terminated prepolymer and a chain extender.

[0024] In the preparation of a polyurethane dispersion, for example, first, an isocyanate group-terminated prepolymer is synthesized. The isocyanate group-terminated prepolymer is a polyurethane prepolymer having two or more free isocyanate groups at the molecular terminals. The isocyanate group-terminated prepolymer is obtained by the reaction of a polyisocyanate component and an active hydrogen group-containing component as described above.

[0025] The polyisocyanate component contains xylylene diisocyanate (XDI) as an essential component.

[0026] Examples of the xylylene diisocyanate include a xylylene diisocyanate monomer (XDI monomer) and a xylylene diisocyanate derivative (XDI derivative).

[0027] Examples of the xylylene diisocyanate monomer include 1,2-xylylene diisocyanate, 1,3-xylylene diisocyanate, and 1,4-xylylene diisocyanate. These xylylene diisocyanate monomers can be used alone or in combination of two or more. Preferred examples of the xylylene diisocyanate monomer include 1,3-xylylene diisocyanate and 1,4-xylylene diisocyanate, and more preferred is 1,3-xylylene diisocyanate.

[0028] Examples of the xylylene diisocyanate derivative include modified products obtained by modifying the above-mentioned xylylene diisocyanate monomer by a known method. More specifically, examples of the xylylene diisocyanate derivative include multimers, allophanate-modified products, polyol-modified products, biuret-modified products, urea-modified products, oxadiazinetrione-modified products, and carbodiimide-modified products. These xylylene diisocyanate derivatives can be used alone or in combination of two or more.

[0029] These xylylene diisocyanates can be used alone or in combination of two or more. Preferred xylylene diisocyanates include xylylene diisocyanate monomers.

[0030] In addition, the polyisocyanate component can contain other polyisocyanates as optional components. Other polyisocyanates are polyisocyanates excluding xylylene diisocyanate.

[0031] Examples of other polyisocyanates include industrially widely used polyisocyanates. More specifically, for example, aromatic polyisocyanates, araliphatic polyisocyanates (excluding xylylene diisocyanate), aliphatic polyisocyanates, and alicyclic polyisocyanates can be mentioned. In addition, other polyisocyanates include derivatives of the same type as described above. These other polyisocyanates can be used alone or in combination of two or more.

[0032] Preferred examples of other polyisocyanates include alicyclic polyisocyanates. Examples of alicyclic polyisocyanates include bis(isocyanatomethyl)cyclohexane (H6XDI), methylene bis(cyclohexyl isocyanate) (H 12 MDI), and isophorone diisocyanate (IPDI). These alicyclic polyisocyanates can be used alone or in combination of two or more.

[0033] Preferred examples of alicyclic polyisocyanates include bis(isocyanatomethyl)cyclohexane (H6XDI), methylene bis(cyclohexyl isocyanate) (H 12 MDI), and more preferably methylene bis(cyclohexyl isocyanate) (H 12 MDI).

[0034] In addition, when the polyisocyanate component contains other polyisocyanates, the ratio of xylylene diisocyanate to the other polyisocyanates is appropriately set within a range that does not impair the excellent effects of the present invention.

[0035] For example, when xylylene diisocyanate and an alicyclic polyisocyanate are used in combination, xylylene diisocyanate is, for example, 50 mol% or more, preferably 60 mol% or more, more preferably 70 mol% or more, still more preferably 80 mol% or more, based on the total moles of them. Also, xylylene diisocyanate is, for example, 99.9 mol% or less, preferably 99 mol% or less, more preferably 95 mol% or less, still more preferably 90 mol% or less, based on the total moles of them.

[0036] Also, when xylylene diisocyanate and an alicyclic polyisocyanate are used in combination, the alicyclic polyisocyanate is, for example, 0.1 mol% or more, preferably 1 mol% or more, more preferably 5 mol% or more, still more preferably 10 mol% or more, based on the total moles of them. Also, it is, for example, 50 mol% or less, preferably 40 mol% or less, more preferably 30 mol% or less, still more preferably 20 mol% or less, based on the total moles of them.

[0037] In particular, when the polyisocyanate component contains xylylene diisocyanate and the chain extender (described later) contains ethylenediamine, the alicyclic polyisocyanate contributes to heat resistance and storage stability. Therefore, when the polyisocyanate component contains xylylene diisocyanate and the chain extender (described later) contains ethylenediamine, if the ratio of the alicyclic polyisocyanate exceeds the above lower limit, a polyurethane resin having more excellent heat resistance can be obtained. Further, therefore, when the polyisocyanate component contains xylylene diisocyanate and the chain extender (described later) contains ethylenediamine, if the ratio of the alicyclic polyisocyanate is below the above upper limit, a polyurethane resin having more excellent storage stability can be obtained.

[0038] Examples of the active hydrogen group-containing component include polyol components. The polyol component contains, as essential components, a short-chain diol having 2 to 6 carbon atoms and an active hydrogen group-containing compound containing a hydrophilic group.

[0039] The short-chain diol having 2 to 6 carbon atoms has two hydroxyl groups and is an organic compound having 2 to 6 carbon atoms. The molecular weight of the short-chain diol is 50 or more and 650 or less. When the short-chain diol has a molecular weight distribution, the molecular weight indicates the number-average molecular weight in terms of polystyrene by GPC measurement.

[0040] Examples of the short-chain diol having 2 to 6 carbon atoms include alkane diols having 2 to 6 carbon atoms, ether diols having 2 to 6 carbon atoms, and alkene diols having 2 to 6 carbon atoms.

[0041] Examples of the alkane diol having 2 to 6 carbon atoms include ethylene glycol, propylene glycol, 1,3-propanediol, 1,4-butanediol, 1,3-butanediol, 1,2-butanediol, 1,5-pentanediol, 1,6-hexanediol, neopentyl glycol, 3-methyl-1,5-pentanediol, 1,3-cyclohexanediol, and 1,4-cyclohexanediol. Examples of the ether diol having 2 to 6 carbon atoms include diethylene glycol, triethylene glycol, and dipropylene glycol. Examples of the alkene diol having 2 to 6 carbon atoms include 1,4-dihydroxy-2-butene. These short-chain diols can be used alone or in combination of two or more. From the viewpoint of gas barrier properties, the short-chain diol is preferably an alkane diol having 2 to 6 carbon atoms, and more preferably ethylene glycol.

[0042] The content ratio of short-chain diols having 2 to 6 carbon atoms is, for example, 10 parts by mass or more, preferably 30 parts by mass or more, more preferably 50 parts by mass or more, and for example, 90 parts by mass or less, preferably 80 parts by mass or less, more preferably 70 parts by mass or less, based on 100 parts by mass of the total amount of the active hydrogen group-containing component.

[0043] The active hydrogen group-containing compound containing a hydrophilic group is a compound containing a hydrophilic group and an active hydrogen group. Examples of the active hydrogen group include a hydroxyl group and an amino group.

[0044] Examples of the hydrophilic group include a nonionic group and an ionic group. More specifically, examples of the active hydrogen group-containing compound containing a hydrophilic group include an active hydrogen group-containing compound containing a nonionic group and an active hydrogen group-containing compound containing an ionic group.

[0045] The active hydrogen group-containing compound containing a nonionic group is a compound having one or more nonionic groups and two or more active hydrogen groups. Examples of the nonionic group include a polyoxyethylene group. Examples of the active hydrogen group-containing compound containing a nonionic group include polyoxyethylene glycol, one-end-blocked polyoxyethylene glycol, and a polyol containing a polyoxyethylene side chain.

[0046] Examples of the active hydrogen group-containing compound containing an ionic group include an active hydrogen group-containing compound containing an anionic group and an active hydrogen group-containing compound containing a cationic group. The active hydrogen group-containing compound containing an anionic group is a compound having one or more anionic groups and two or more active hydrogen groups. Examples of the anionic group include a carboxy group (carboxylic acid group) and a sulfo group (sulfonic acid group). The active hydrogen group-containing compound containing a cationic group is a compound having one or more cationic groups and two or more active hydrogen groups. Examples of the cationic group include a quaternary ammonium group.

[0047] These active hydrogen group-containing compounds containing hydrophilic groups can be used alone or in combination of two or more. As the active hydrogen group-containing compound containing a hydrophilic group, preferably, an active hydrogen group-containing compound containing an anionic group can be mentioned.

[0048] In the active hydrogen group-containing compound containing an anionic group, examples of the anionic group include a carboxy group (carboxylic acid group) and a sulfo group (sulfonic acid group).

[0049] From the viewpoints of gas barrier properties and water resistance, as the anionic group, preferably, a carboxy group can be mentioned. In the active hydrogen group-containing compound containing an anionic group, examples of the active hydrogen group include a hydroxyl group and an amino group, and preferably, a hydroxyl group can be mentioned. That is, as the active hydrogen group-containing compound containing an anionic group, preferably, an organic compound having both a carboxy group and two hydroxyl groups can be mentioned.

[0050] Examples of the organic compound having both a carboxy group and two hydroxyl groups include carboxy group-containing polyols. Examples of the carboxy group-containing polyol include polyhydroxyalkanoic acids. Examples of the polyhydroxyalkanoic acid include 2,2-dimethylolacetic acid, 2,2-dimethylollactic acid, 2,2-dimethylolpropionic acid (also known as dimethylolpropionic acid), 2,2-dimethylolbutanoic acid, 2,2-dimethylolbutyric acid, and 2,2-dimethylolvaleric acid. These organic compounds having both a carboxy group and two hydroxyl groups can be used alone or in combination of two or more. As the organic compound having both a carboxy group and two hydroxyl groups, preferably, 2,2-dimethylolpropionic acid can be mentioned.

[0051] The content ratio of the active hydrogen group-containing compound containing a hydrophilic group is, for example, 10 parts by mass or more, preferably 20 parts by mass or more, and for example, 50 parts by mass or less, preferably 40 parts by mass or less, based on 100 parts by mass of the total amount of the active hydrogen group-containing components.

[0052] In addition, the polyol component can further contain other low molecular weight polyols as optional components. The other low molecular weight polyols are low molecular weight polyols excluding short-chain diols having 2 to 6 carbon atoms and active hydrogen group-containing compounds containing hydrophilic groups. The low molecular weight polyol is a relatively low molecular weight organic compound having two or more hydroxyl groups in the molecule. The molecular weight of the low molecular weight polyol is 50 or more and 650 or less, preferably 500 or less. Examples of the other low molecular weight polyols include diols having 7 or more carbon atoms and low molecular weight polyols having trivalent or higher valences.

[0053] Examples of the diols having 7 or more carbon atoms include alkane (7 to 20 carbon atoms)-1,2-diol, 2,6-dimethyl-1-octene-3,8-diol, 1,3-cyclohexanedimethanol, 1,4-cyclohexanedimethanol, hydrogenated bisphenol A, and bisphenol A. These diols having 7 or more carbon atoms can be used alone or in combination of two or more.

[0054] Examples of the low molecular weight polyols having trivalent or higher valences include trivalent alcohols and tetravalent alcohols. Examples of the trivalent alcohols include glycerin, 2-methyl-2-hydroxymethyl-1,3-propanediol, 2,4-dihydroxy-3-hydroxymethylpentane, 1,2,6-hexanetriol, trimethylolpropane, and 2,2-bis(hydroxymethyl)-3-butanol. Examples of the tetravalent alcohols include tetramethylolmethane (pentaerythritol) and diglycerin. These low molecular weight polyols having trivalent or higher valences can be used alone or in combination of two or more.

[0055] Furthermore, examples of the other low molecular weight polyols include polyether polyols having a number average molecular weight of 650 or less, polyester polyols having a number average molecular weight of 650 or less, and polycarbonate polyols having a number average molecular weight of 650 or less.

[0056] Other low molecular weight polyols can be used alone or in combination of two or more. From the viewpoints of water resistance and water dispersion stability, the other low molecular weight polyols preferably include low molecular weight polyols having three or more hydroxyl groups, more preferably trihydric alcohols, and particularly preferably trimethylolpropane.

[0057] When the active hydrogen group-containing component contains an alcohol having three or more hydroxyl groups, the proportion of the alcohol having three or more hydroxyl groups relative to the total amount of the active hydrogen group-containing component is, for example, 0.1 mol% or more, preferably 1 mol% or more, more preferably 3 mol% or more, and is, for example, 30 mol% or less, preferably 15 mol% or less, more preferably 10 mol% or less.

[0058] In particular, when the polyisocyanate component contains xylylene diisocyanate and the chain extender (described later) contains ethylenediamine, the alcohol having three or more hydroxyl groups contributes to heat resistance, storage stability, and ease of production. Therefore, when the polyisocyanate component contains xylylene diisocyanate and the chain extender (described later) contains ethylenediamine, if the proportion of the alcohol having three or more hydroxyl groups exceeds the above lower limit, a polyurethane resin having more excellent heat resistance and storage stability can be obtained. Further, when the polyisocyanate component contains xylylene diisocyanate and the chain extender (described later) contains ethylenediamine, if the proportion of the alcohol having three or more hydroxyl groups is below the above upper limit, a polyurethane resin having more excellent ease of production can be obtained.

[0059] The molar ratio of the alcohol having three or more hydroxyl groups in the active hydrogen group-containing component is calculated by a known method based on the hydroxyl equivalent (molecular weight / hydroxyl number) and the blending amount.

[0060] Also, when the active hydrogen group-containing component contains other low molecular weight polyols, the content ratio of the other low molecular weight polyols is, for example, 0.2 parts by mass or more, preferably 1 part by mass or more, more preferably 2 parts by mass or more, based on 100 parts by mass of the total amount of the active hydrogen group-containing component, and is, for example, 20 parts by mass or less, preferably 10 parts by mass or less, more preferably 8 parts by mass or less.

[0061] In addition, the combined ratio of the short-chain diol having 2 to 6 carbon atoms and the other low molecular weight polyols is such that the other low molecular weight polyols are, for example, 2 parts by mass or more, preferably 5 parts by mass or more, based on 100 parts by mass of their total amount, and is, for example, 20 parts by mass or less, preferably 15 parts by mass or less, more preferably 10 parts by mass or less.

[0062] Also, the active hydrogen group-containing compound containing a hydrophilic group is, for example, 10 parts by mass or more, preferably 20 parts by mass or more, more preferably 40 parts by mass or more, based on 100 parts by mass of the total amount of the short-chain diol having 2 to 6 carbon atoms and the other low molecular weight polyols, and is, for example, 90 parts by mass or less, preferably 80 parts by mass or less, more preferably 70 parts by mass or less.

[0063] If the content ratio of the other low molecular weight polyols is within the above range, excellent dispersibility can be ensured.

[0064] In addition, the polyol component can further contain a high molecular weight polyol as an optional component. The high molecular weight polyol has two or more hydroxyl groups in the molecule and is a relatively high molecular weight organic compound (polymer). The number average molecular weight of the high molecular weight polyol exceeds, for example, 650 and is, for example, 20,000 or less. Examples of the high molecular weight polyol include polyether polyol, polyester polyol, polycarbonate polyol, polyurethane polyol, epoxy polyol, vegetable oil polyol, polyolefin polyol, acrylic polyol, and vinyl monomer-modified polyol. These high molecular weight polyols can be used alone or in combination of two or more.

[0065] However, high molecular weight polyols may reduce the gas barrier properties of polyurethane resins (described later). Therefore, the polyol component preferably does not contain high molecular weight polyols.

[0066] That is, the polyol component preferably consists of short-chain diols having 2 to 6 carbon atoms, low molecular weight polyols having a trivalent or higher valence, and active hydrogen group-containing compounds containing hydrophilic groups, or consists of short-chain diols having 2 to 6 carbon atoms and active hydrogen group-containing compounds containing hydrophilic groups. More preferably, the polyol component consists of short-chain diols having 2 to 6 carbon atoms, low molecular weight polyols having a trivalent or higher valence, and active hydrogen group-containing compounds containing anionic groups, or consists of short-chain diols having 2 to 6 carbon atoms and active hydrogen group-containing compounds containing anionic groups.

[0067] The isocyanate group-terminated prepolymer is obtained by reacting the above components in a predetermined equivalent ratio. In the synthesis of the isocyanate group-terminated prepolymer, the equivalent ratio refers to the equivalent ratio of the isocyanate group to the active hydrogen group (hydroxyl group) (isocyanate group / active hydrogen group).

[0068] The equivalent ratio (isocyanate group / active hydrogen group) exceeds, for example, 1, and preferably is 1.1 or more. Also, the equivalent ratio (isocyanate group / active hydrogen group) is, for example, 20 or less, and preferably 10 or less.

[0069] In addition, in the synthesis of the isocyanate group-terminated prepolymer, a known polymerization method is adopted.

[0070] Examples of the polymerization method include bulk polymerization and solution polymerization.

[0071] From the viewpoint of adjusting reactivity, solution polymerization is preferably adopted as the polymerization method.

[0072] In bulk polymerization, for example, the above components are compounded and reacted under a nitrogen atmosphere. The reaction temperature is, for example, 75 to 85°C. The reaction time is, for example, 1 to 20 hours.

[0073] In solution polymerization, for example, the above components are compounded and reacted in an organic solvent under a nitrogen atmosphere. The reaction temperature is, for example, 20 to 80°C. The reaction time is, for example, 1 to 20 hours.

[0074] Examples of the organic solvent include solvents that are inert to isocyanate groups. Examples of the organic solvent include acetone, methyl ethyl ketone, ethyl acetate, tetrahydrofuran, and acetonitrile. These organic solvents can be used alone or in combination of two or more.

[0075] In addition, in the above polymerization, a catalyst can be added as needed. Examples of the catalyst include amine-based catalysts and organometallic catalysts. These catalysts can be used alone or in combination of two or more. The addition amount of the catalyst is appropriately set according to the purpose and application.

[0076] In addition, in this method, the above polymerization is terminated, for example, when the isocyanate group concentration in the reaction product reaches the range described below. In this method, the unreacted polyisocyanate component can be removed by a known removal method. Examples of the removal method include distillation and extraction.

[0077] Thereby, an isocyanate group-terminated prepolymer is obtained.

[0078] The isocyanate group concentration of the isocyanate group-terminated prepolymer is, for example, 4% by mass or more, preferably 5% by mass or more, more preferably 6% by mass or more. Also, the isocyanate group concentration of the isocyanate group-terminated prepolymer is, for example, 25% by mass or less, preferably 20% by mass or less, more preferably 17% by mass or less, and still more preferably 15% by mass or less.

[0079] In addition, the average functionality of the isocyanate groups is, for example, 1.5 or more, preferably 1.9 or more, more preferably 2.0 or more. Also, the average functionality of the isocyanate groups is, for example, 3.0 or less, preferably 2.5 or less.

[0080] When the isocyanate group-terminated prepolymer contains an anionic group, for example, a neutralizing agent is added to the isocyanate group-terminated prepolymer for neutralization to form a salt of the anionic group. Examples of the neutralizing agent include conventional bases. Specific examples of the base include organic bases and inorganic bases.

[0081] Examples of the organic base include tertiary amines and secondary amines. Examples of the tertiary amine include trialkylamines and alkanolamines. Examples of the trialkylamine include trialkylamines having 1 to 4 carbon atoms. Such trialkylamines include, for example, trimethylamine and triethylamine. Examples of the alkanolamine include dimethylethanolamine, methyldiethanolamine, triethanolamine, and triisopropanolamine. Examples of the secondary amine include heterocyclic amines. Examples of the heterocyclic amine include morpholine. These organic bases can be used alone or in combination of two or more.

[0082] Examples of the inorganic base include ammonia, alkali metal hydroxides, alkaline earth metal hydroxides, and alkali metal carbonates. Examples of the alkali metal hydroxide include lithium hydroxide, sodium hydroxide, and rubidium hydroxide. Examples of the alkaline earth metal hydroxide include magnesium hydroxide and calcium hydroxide. Examples of the alkali metal carbonate include sodium carbonate and potassium carbonate. These inorganic bases can be used alone or in combination of two or more.

[0083] These neutralizing agents can be used alone or in combination of two or more. Preferred neutralizing agents include organic bases, more preferably tertiary amines, even more preferably trialkylamines, and most preferably triethylamine.

[0084] The addition amount of the neutralizing agent is, for example, 0.4 equivalent or more, preferably 0.6 equivalent or more, relative to 1 equivalent of the anionic group. Also, the addition amount of the neutralizing agent is, for example, 1.2 equivalents or less, preferably 1.0 equivalent or less, relative to 1 equivalent of the anionic group.

[0085] Next, in this method, an isocyanate group-terminated prepolymer (primary reaction product) and a chain extender are reacted to obtain a gas barrier polyurethane resin (secondary reaction product).

[0086] For example, by reacting an isocyanate group-terminated prepolymer and a chain extender in water, a polyurethane dispersion can be obtained.

[0087] The chain extender has a plurality of active hydrogen groups and is an organic compound that causes a chain extension reaction of the isocyanate group-terminated prepolymer.

[0088] The chain extender contains ethylenediamine as an essential component.

[0089] When the chain extender contains ethylenediamine and the polyisocyanate component contains xylylene diisocyanate, a polyurethane resin excellent in gas barrier properties, heat resistance, and storage stability can be obtained due to their excellent crystallinity.

[0090] Also, the chain extender can contain other chain extenders as optional components. The other chain extenders are chain extenders other than ethylenediamine. Examples of the other chain extenders include polyamines and amino alcohols.

[0091] Examples of the polyamine include aromatic polyamine, araliphatic polyamine, alicyclic polyamine, aliphatic polyamine (excluding ethylenediamine), and polyoxyethylene group-containing polyamine.

[0092] Examples of the aromatic polyamine include 4,4'-diphenylmethanediamine and tolylenediamine.

[0093] Examples of the araliphatic polyamine include 1,3-xylylenediamine and 1,4-xylylenediamine.

[0094] Examples of the alicyclic polyamine include 3-aminomethyl-3,5,5-trimethylcyclohexylamine (alias: isophoronediamine), 4,4'-dicyclohexylmethanediamine, 2,5-bis(aminomethyl)bicyclo[2.2.1]heptane, 2,6-bis(aminomethyl)bicyclo[2.2.1]heptane, 1,4-cyclohexanediamine, 1-amino-3-aminomethyl-3,5,5-trimethylcyclohexane, bis-(4-aminocyclohexyl)methane, diaminocyclohexane, 3,9-bis(3-aminopropyl)-2,4,8,10-tetraoxaspiro[5,5]undecane, 1,3-bis(aminomethyl)cyclohexane, and 1,4-bis(aminomethyl)cyclohexane.

[0095] Examples of the aliphatic polyamine include propylenediamine, 1,3-propanediamine, 1,4-butanediamine, 1,5-pentanediamine, 1,6-hexamethylenediamine, hydrazine, hydrazine hydrate, diethylenetriamine, triethylenetetramine, tetraethylenepentamine, 1,2-diaminoethane, 1,2-diaminopropane, and 1,3-diaminopentane.

[0096] Examples of the polyoxyethylene group-containing polyamine include polyoxyalkylene ether diamine. Examples of the polyoxyalkylene ether diamine include polyoxyethylene ether diamine. More specifically, for example, PEG#1000 diamine (manufactured by NOF Corporation), Jeffamine ED-2003 (manufactured by Huntsman Corporation), Jeffamine EDR-148 (manufactured by Huntsman Corporation), and Jeffamine XTJ-512 (manufactured by Huntsman Corporation) can be mentioned.

[0097] Examples of the amino alcohol include 2-((2-aminoethyl)amino)ethanol (alias: N-(2-aminoethyl)ethanolamine) and 2-((2-aminoethyl)amino)-1-methylpropanol (alias: N-(2-aminoethyl)isopropanolamine).

[0098] In addition, examples of other chain extenders further include alkoxysilyl compounds having a primary amino group, alkoxysilyl compounds having a primary amino group and a secondary amino group, and the like.

[0099] Examples of the alkoxysilyl compound having a primary amino group include γ-aminopropyltrimethoxysilane, γ-aminopropyltriethoxysilane, and N-phenyl-γ-aminopropyltrimethoxysilane.

[0100] Examples of the alkoxysilyl compound having a primary amino group and a secondary amino group include N-β(aminoethyl)γ-aminopropyltrimethoxysilane (also known as N-2-(aminoethyl)-3-aminopropyltrimethoxysilane), N-β(aminoethyl)γ-aminopropyltriethoxysilane (also known as N-2-(aminoethyl)-3-aminopropyltriethoxysilane), N-β(aminoethyl)γ-aminopropylmethyldimethoxysilane (also known as N-2-(aminoethyl)-3-aminopropylmethyldimethoxysilane), and N-β(aminoethyl)γ-aminopropylmethyldiethoxysilane (also known as N-2-(aminoethyl)-3-aminopropylmethyldiethoxysilane).

[0101] Other chain extenders can be used alone or in combination of two or more.

[0102] Preferred examples of other chain extenders include amino alcohols, and more preferred is 2-((2-aminoethyl)amino)ethanol.

[0103] In the chain extender, the content ratio of ethylenediamine is 25 mol% or more, preferably 30 mol% or more, more preferably 50 mol% or more, still more preferably 70 mol% or more, still more preferably 90 mol% or more, particularly preferably 100 mol%, based on the total amount of the chain extender.

[0104] When the content ratio of ethylenediamine is less than 100 mol%, the balance is other chain extenders.

[0105] When the content ratio of ethylenediamine is within the above range and the polyisocyanate component contains xylylene diisocyanate, a polyurethane resin excellent in gas barrier properties, heat resistance, and storage stability can be obtained due to their excellent crystallinity.

[0106] Note that a polyurethane resin containing ethylenediamine and other chain extenders as chain extenders can be obtained, for example, by adding ethylenediamine and other chain extenders all at once or sequentially in the chain extension reaction described below.

[0107] Also, for example, a polyurethane resin containing ethylenediamine and other chain extenders as chain extenders can be obtained by mixing, for example, a polyurethane resin chain-extended with ethylenediamine and a polyurethane resin chain-extended with other chain extenders.

[0108] In the chain extension reaction, for example, an isocyanate group-terminated prepolymer and a chain extender are reacted in water.

[0109] More specifically, for example, first, the isocyanate group-terminated prepolymer is dispersed in water.

[0110] Next, a chain extender is added to the aqueous dispersion of the isocyanate group-terminated prepolymer to chain-extend the isocyanate group-terminated prepolymer with the chain extender. The method of dispersing the isocyanate group-terminated prepolymer in water is not particularly limited. For example, the isocyanate group-terminated prepolymer is added to water while stirring the water. In this case, the amount of water is 100 to 1000 parts by mass with respect to 100 parts by mass of the isocyanate group-terminated prepolymer.

[0111] Thereafter, while stirring the water in which the isocyanate group-terminated prepolymer is dispersed, the chain extender is dropped into the water. In this case, the equivalent ratio of the active hydrogen group of the chain extender to the isocyanate group of the isocyanate group-terminated prepolymer (active hydrogen group / isocyanate group) is, for example, 0.6 to 1.2. The chain extension reaction is completed, for example, at room temperature. The time until the completion of the reaction is, for example, 0.1 to 10 hours.

[0112] Also, in this method, after the reaction is completed, the organic solvent and / or water can be removed to adjust the solid content concentration. Also, in this method, water can be added after the reaction is completed to adjust the solid content concentration.

[0113] Furthermore, in this method, a solvent can be added to adjust the solid content concentration. Examples of the solvent include water, methanol, ethanol, propanol, isopropanol, acetone, methyl ethyl ketone, ethyl acetate, tetrahydrofuran, acetonitrile, and the like. These solvents can be used alone or in combination of two or more.

[0114] Thereby, a polyurethane dispersion (PUD) can be obtained.

[0115] The solid content concentration of the polyurethane dispersion is, for example, 10% by mass or more, preferably 15% by mass or more, more preferably 20% by mass or more. Also, the solid content concentration of the polyurethane dispersion is, for example, 60% by mass or less, preferably 50% by mass or less, more preferably 40% by mass or less.

[0116] The pH of the polyurethane dispersion is, for example, 5 or more, preferably 6 or more. Also, the pH of the polyurethane dispersion is, for example, 11 or less, preferably 10 or less.

[0117] The average particle diameter of the polyurethane dispersion is, for example, 10 nm or more, preferably 20 nm or more, more preferably 50 nm or more. Also, the average particle diameter of the polyurethane dispersion is, for example, 500 nm or less, preferably 300 nm or less, more preferably 200 nm or less.

[0118] Also, in the polyurethane dispersion, the total of the urethane group concentration and the urea group concentration is relatively high. By increasing the urethane group concentration and the urea group concentration, the gas barrier property can be improved.

[0119] The total of the urethane group concentration and the urea group concentration is, for example, 30% by mass or more, preferably 34% by mass or more, more preferably 38% by mass or more. Also, the total of the urethane group concentration and the urea group concentration is, for example, 50% by mass or less, preferably 46% by mass or less, more preferably 42% by mass or less. Note that the total of the urethane group concentration and the urea group concentration can be calculated from the charging ratio of the raw material components.

[0120] Also, the polyurethane dispersion can contain an additive.

[0121] Examples of the additive include a filler, a silane coupling agent (excluding the epoxy silane described later), an alkoxysilane compound, a thickener, an antioxidant, a heat stabilizer, an ultraviolet absorber, a plasticizer, an antistatic agent, a lubricant, an antiblocking agent, a surfactant, a dispersion stabilizer, a colorant, a pigment, a dye, colloidal silica, inorganic particles, inorganic oxide particles, a layered inorganic compound, a leveling agent, a crystal nucleating agent, a crosslinking agent, and a curing agent. These additives can be used alone or in combination of two or more. Note that the blending ratio of the additive is not particularly limited and is appropriately set according to the purpose and application.

[0122] In such a polyurethane dispersion, the polyisocyanate component contains xylylene diisocyanate, and the chain extender contains ethylenediamine in a predetermined ratio.

[0123] Therefore, the polyurethane dispersion contains a polyurethane resin excellent in gas barrier properties, heat resistance, and storage stability.

[0124] The heat resistance of the polyurethane resin is evaluated by, for example, the coefficient of thermal expansion.

[0125] The coefficient of thermal expansion of the polyurethane resin is, for example, 2000×10 -6 K -1 or less, preferably 1500×10 -6 K -1 or less, more preferably 1000×10 -6 K -1Hereinafter, more preferably, 500 × 10 -6 K -1 Hereinafter, particularly preferably, 100 × 10 -6 K -1 or less. Further, the coefficient of thermal expansion of the polyurethane resin is usually 1 × 10 -6 K -1 or more.

[0126] Note that the coefficient of thermal expansion of the polyurethane resin is measured using a film of the polyurethane resin in accordance with the examples described later.

[0127] And according to the above polyurethane dispersion, a polyurethane layer excellent in gas barrier properties, heat resistance, and storage stability can be formed.

[0128] Therefore, the above polyurethane dispersion is suitably used as a gas barrier coating material.

[0129] The gas barrier coating material contains the above polyurethane dispersion.

[0130] In addition, the gas barrier coating material can contain additives. Examples of the additives include fillers, silane coupling agents (excluding the epoxy silane described later), alkoxysilane compounds, thickeners, antioxidants, heat stabilizers, ultraviolet absorbers, plasticizers, antistatic agents, lubricants, antiblocking agents, surfactants, dispersion stabilizers, colorants, pigments, dyes, colloidal silica, inorganic particles, inorganic oxide particles, layered inorganic compounds, leveling agents, crystal nucleating agents, crosslinking agents, and curing agents. These additives can be used alone or in combination of two or more. Note that the blending ratio of the additives is not particularly limited and is appropriately set according to the purpose and application.

[0131] In polyurethane dispersions and gas barrier coating materials, preferred additives include curing agents. Examples of curing agents include epoxy curing agents, melamine curing agents, carbodiimide curing agents, aziridine curing agents, oxazoline curing agents, isocyanate curing agents, and reactive curing agents. These can be used alone or in combination of two or more.

[0132] When the polyurethane resin contains a carboxy group as a hydrophilic group, preferred curing agents include epoxy curing agents, carbodiimide curing agents, and isocyanate curing agents.

[0133] An epoxy curing agent is a compound having an epoxy group. Examples of epoxy curing agents include known epoxy curing agents, and preferably epoxy silanes. When the polyurethane dispersion and the gas barrier coating material contain an epoxy curing agent, a polyurethane layer excellent in heat and humidity resistance (retort resistance) can be obtained. In particular, in the above polyurethane dispersion and the above gas barrier coating material, the chain extender contains ethylenediamine. Therefore, the epoxy curing agent can more effectively improve the heat and humidity resistance (retort resistance) of the polyurethane layer.

[0134] Examples of epoxy silanes include silane coupling agents containing an epoxy group. More specifically, examples of epoxy silanes include 3-glycidoxypropyltrimethoxysilane, 3-glycidoxypropyltriethoxysilane, 3-glycidoxypropylmethyldimethoxysilane, 3-glycidoxypropylmethyldiethoxysilane, and 2-(3,4-epoxycyclohexyl)ethyltrimethoxysilane. These can be used alone or in combination of two or more. Preferred epoxy silanes include trialkoxysilanes, and more preferably 3-glycidoxypropyltrimethoxysilane.

[0135] Epoxysilanes are also available as commercial products. More specifically, examples of commercial products include KBM-403 (glycidoxypropyltrimethoxysilane), KBE-403 (3-glycidoxypropyltriethoxysilane), KBM-402 (3-glycidoxypropylmethyldimethoxysilane), KBE-402 (3-glycidoxypropylmethyldiethoxysilane), and KBM-303 (2-(3,4-epoxycyclohexyl)ethyltrimethoxysilane) (all manufactured by Shin-Etsu Chemical Co., Ltd.). These can be used alone or in combination of two or more.

[0136] When an epoxy curing agent (preferably an epoxysilane) is used, the addition amount of the epoxy curing agent is appropriately set according to the purpose and application. For example, when the polyurethane resin contains a carboxy group as a hydrophilic group, with respect to 1.0 mol of the carboxy group in the polyurethane resin, the epoxy group in the epoxy curing agent is, for example, 0.1 mol or more, preferably 0.3 mol or more, more preferably 0.5 mol or more, still more preferably 0.8 mol or more. Also, with respect to 1.0 mol of the carboxy group in the polyurethane resin, the epoxy group in the epoxy curing agent is, for example, 5.0 mol or less, preferably 3.0 mol or less, more preferably 2.1 mol or less, still more preferably 1.5 mol or less, particularly preferably 1.2 mol or less.

[0137] Also, with respect to 100 parts by mass of the total solid content of the polyurethane dispersion and / or the gas barrier coating material, the epoxy curing agent is, for example, 1.0 part by mass or more, preferably 3.0 part by mass or more, more preferably 5.0 part by mass or more. Also, with respect to 100 parts by mass of the total solid content, the epoxy curing agent is, for example, 50.0 part by mass or less, preferably 40.0 part by mass or less, more preferably 30.0 part by mass or less, still more preferably 20.0 part by mass or less.

[0138] The carbodiimide curing agent is a compound having a carbodiimide group (carbodiimide compound). If the polyurethane dispersion and the gas barrier coating material contain a carbodiimide curing agent, a polyurethane layer excellent in heat and humidity resistance (retort resistance) can be obtained. In particular, in the above polyurethane dispersion and the above gas barrier coating material, the chain extender contains ethylenediamine. Therefore, the carbodiimide curing agent can more effectively improve the heat and humidity resistance (retort resistance) of the polyurethane layer.

[0139] When a carbodiimide curing agent (carbodiimide compound) is used, the addition amount of the carbodiimide curing agent is appropriately set according to the purpose and application. For example, when the polyurethane resin contains a carboxy group as a hydrophilic group, with respect to 1.0 mol of the carboxy group in the polyurethane resin, the carbodiimide group in the carbodiimide curing agent is, for example, 0.05 mol or more, preferably 0.1 mol or more, more preferably 0.3 mol or more, still more preferably 0.5 mol or more, still more preferably 0.7 mol or more, particularly preferably 0.9 mol or more. Also, with respect to 1.0 mol of the carboxy group in the polyurethane resin, the carbodiimide group in the carbodiimide curing agent is, for example, 3.0 mol or less, preferably 2.0 mol or less, more preferably 1.5 mol or less, still more preferably 1.2 mol or less, particularly preferably 1.0 mol or less.

[0140] Also, with respect to 100 parts by mass of the total solid content of the polyurethane dispersion and / or the gas barrier coating material, the carbodiimide curing agent is, for example, 1.0 part by mass or more, preferably 5.0 part by mass or more, more preferably 9.0 part by mass or more, still more preferably 13.0 part by mass or more, particularly preferably 16.0 part by mass or more. Also, with respect to 100 parts by mass of the total solid content, the carbodiimide curing agent is, for example, 70.0 part by mass or less, preferably 65.0 part by mass or less, more preferably 47.0 part by mass or less, still more preferably 45.0 part by mass, still more preferably 38.0 part by mass or less, particularly preferably 32.0 part by mass or less.

[0141] The carbodiimide curing agent is also available as a commercial product. Examples of commercial products of the carbodiimide curing agent include Carbodilite V-02, Carbodilite V-02-L2, Carbodilite SV-02, Carbodilite V-04, Carbodilite V-10, Carbodilite SW-12G, Carbodilite E-02, Carbodilite E-03A, Carbodilite E-05 (manufactured by Nisshinbo Chemical Inc.), Lupranate MM-103, XTB-3003 (manufactured by BASF), Stabaxol P (manufactured by Sumitomo Bayer Urethane), PICASSIAN XL-701, XL-702, XL-721, XL-725, XL-732, XL-752, XL-755, and XL-782 (manufactured by STAHL POLYMERS).

[0142] Examples of the isocyanate curing agent include known isocyanate curing agents, preferably water-dispersible polyisocyanates. If the polyurethane dispersion and the gas barrier coating material contain the isocyanate curing agent, a polyurethane layer excellent in moisture and heat resistance (retort resistance) can be obtained. In particular, in the above polyurethane dispersion and the above gas barrier coating material, the chain extender contains ethylenediamine. Therefore, the isocyanate curing agent can more effectively improve the moisture and heat resistance (retort resistance) of the polyurethane layer.

[0143] The water-dispersible polyisocyanate is a polyisocyanate dispersible in water. Examples of the water-dispersible polyisocyanate include polyisocyanates having an alkylene oxide group having 2 to 3 carbon atoms as a repeating unit. These can be used alone or in combination of two or more.

[0144] The water-dispersible polyisocyanate can be obtained, for example, by dispersing a polyisocyanate containing a polyethylene oxide group in water with a known dispersant (ionic dispersant, nonionic dispersant, etc.). The water-dispersible polyisocyanate can be used alone or in combination of two or more.

[0145] When an isocyanate curing agent is used, the addition amount of the isocyanate curing agent is appropriately set according to the purpose and application. For example, when the polyurethane resin contains a carboxy group as a hydrophilic group, for 1.0 mol of the carboxy group in the polyurethane resin, the isocyanate group in the isocyanate curing agent is, for example, 0.1 mol or more, preferably 0.5 mol or more, more preferably 0.8 mol or more, still more preferably 1.0 mol or more. Also, for 1.0 mol of the carboxy group in the polyurethane resin, the isocyanate group in the isocyanate curing agent is, for example, 5.0 mol or less, preferably 4.0 mol or less, more preferably 3.0 mol or less, still more preferably 2.1 mol or less, particularly preferably 1.8 mol or less.

[0146] Also, based on 100 parts by mass of the total solid content of the polyurethane dispersion and / or the gas barrier coating material, the isocyanate curing agent is, for example, 1.0 part by mass or more, preferably 3.0 part by mass or more, more preferably 5.0 part by mass or more. Also, based on 100 parts by mass of the total solid content, the isocyanate curing agent is, for example, 50.0 part by mass or less, preferably 40.0 part by mass or less, more preferably 30.0 part by mass or less, still more preferably 20.0 part by mass or less.

[0147] The isocyanate curing agent is also available as a commercial product. Examples of commercial products of the isocyanate curing agent include Takenate WD-720, Takenate WD-725, Takenate WD-220, Takenate XWD-HS7, Takenate XWD-HS30 (above, manufactured by Mitsui Chemicals, Inc.), Aquanate 100, Aquanate 110, Aquanate 200, Aquanate 210, etc. (manufactured by Nippon Polyurethane Industry Co., Ltd.), Duranate WB40-100, Duranate WT20-100 (above, manufactured by Asahi Kasei Chemicals Corporation), Bayhydur 3100, Bayhydur XP2487 / 1 (above, manufactured by Bayer MaterialScience), Basonat HW100, and Basonat HA100 (above, manufactured by BASF).

[0148] From the viewpoint of improving the wet heat resistance (retort resistance), as the curing agent, preferably, epoxy silane, water-dispersible polyisocyanate, and carbodiimide compound can be mentioned. In other words, the polyurethane dispersion preferably contains at least one selected from the group consisting of epoxy silane, water-dispersible polyisocyanate, and carbodiimide compound. If the polyurethane dispersion and the gas barrier coating material contain these curing agents, a polyurethane layer excellent in wet heat resistance (retort resistance) can be obtained.

[0149] From the viewpoint of improving the wet heat resistance (retort resistance), more preferably, a carbodiimide compound can be mentioned as the curing agent. In other words, the polyurethane dispersion more preferably contains a carbodiimide compound.

[0150] The timing of adding the curing agent is not particularly limited. For example, the curing agent may be added to the polyurethane dispersion and the gas barrier coating material before storage. Also, the curing agent may be added to, for example, the polyurethane dispersion and the gas barrier coating material after storage (that is, the polyurethane dispersion and the gas barrier coating material immediately before use).

[0151] When the curing agent is added to the polyurethane dispersion and the gas barrier coating material after storage, storage stability is required in the state before the addition of the curing agent. In other words, it is sufficient that the polyurethane dispersion before the addition of the curing agent is excellent in storage stability.

[0152] Further, the solid content concentration of the gas barrier coating material can also be adjusted by removing water from the polyurethane dispersion. Also, the solid content concentration of the gas barrier coating material can be adjusted by adding water to the polyurethane dispersion. Furthermore, the solid content concentration of the gas barrier coating material can also be adjusted by adding the above solvent to the polyurethane dispersion.

[0153] The solid content concentration of the gas barrier coating material is, for example, 10% by mass or more, preferably 15% by mass or more, more preferably 20% by mass or more. Also, the solid content concentration of the polyurethane dispersion is, for example, 60% by mass or less, preferably 50% by mass or less, more preferably 40% by mass or less.

[0154] Since such a gas barrier coating material contains the above polyurethane dispersion, a polyurethane layer excellent in gas barrier properties, heat resistance and storage stability can be formed. Therefore, the gas barrier coating material can be suitably used in the production of a laminate provided with a polyurethane layer as a gas barrier layer.

[0155] In FIG. 1, the laminate 1 includes a substrate 2 and a polyurethane layer 3 disposed on the surface of the substrate 2. Examples of the substrate 2 include plastic, metal vapor-deposited plastic, paper, cloth, wood, metal and ceramics. These can be used alone or in combination of two or more.

[0156] Preferred examples of the substrate 2 include plastic, metal vapor-deposited plastic and paper.

[0157] Examples of the plastic include thermoplastic resins and thermosetting resins, and preferably, thermoplastic resins. Examples of the thermoplastic resin include polyolefin resins, polyester resins, polyamide resins, vinyl resins, acrylic resins, polycarbonate resins, and cellulose resins. These can be used alone or in combination of two or more. Preferably, the thermoplastic resin includes polyolefin resins, polyester resins, and polyamide resins.

[0158] Examples of the base material 2 include an unstretched base material, a uniaxially stretched base material, and a biaxially stretched base material. The base material 2 may be a single layer or a plurality of layers. The base material 2 may be surface-treated. Examples of the surface treatment include corona discharge treatment and anchor coat treatment.

[0159] Examples of the shape of the base material 2 include film shape, sheet shape, bottle shape, and cup shape. Preferably, the film shape is included.

[0160] The thickness of the base material 2 is, for example, 3 μm or more, preferably 5 μm or more. Also, the thickness of the base material 2 is, for example, 500 μm or less, preferably 200 μm or less.

[0161] The polyurethane layer 3 contains the above polyurethane resin and is preferably formed from the above polyurethane resin. Preferably, the polyurethane layer 3 is the dried product of a gas barrier coating material.

[0162] That is, from the viewpoint of manufacturing efficiency, the polyurethane layer 3 is preferably formed by applying and drying a gas barrier coating material onto the base material 2. More specifically, to form the polyurethane layer 3, the above-described gas barrier coating material is applied onto the base material 2 and dried. The coating method of the gas barrier coating material is not particularly limited. Examples of the coating method include a dip coating method, a gravure coating method, a reverse coating method, a roll coating method, a bar coating method, a spray coating method, an air knife coating method, and an in-line coating method.

[0163] The drying conditions of the barrier coating material are not particularly limited. For example, the drying temperature is, for example, 40°C or higher, preferably 50°C or higher. Also, the drying temperature is, for example, 200°C or lower, preferably 180°C or lower. Further, the drying time is, for example, 0.1 minute or longer, preferably 0.2 minute or longer. Also, the drying time is, for example, 10 minutes or shorter, preferably 5 minutes or shorter.

[0164] Thereby, a polyurethane layer 3 made of a polyurethane resin is formed on the base material 2. As a result, a laminate 1 including the base material 2 and the polyurethane layer 3 is obtained.

[0165] Also, the polyurethane layer 3 can be cured as needed.

[0166] The curing conditions of the polyurethane layer 3 are not particularly limited. For example, the curing temperature is, for example, 20°C or higher, preferably 30°C or higher. Also, the curing temperature is, for example, 100°C or lower, preferably 80°C or lower. Further, the curing time is, for example, 1 hour or longer, preferably 10 hours or longer. Also, the curing time is, for example, 10 days or shorter, preferably 7 days or shorter.

[0167] The laminated amount of the polyurethane layer 3 is, for example, 0.1 g / m 2 or more, preferably 0.2 g / m 2 or more, more preferably 0.3 g / m 2 or more. Also, the laminated amount of the polyurethane layer 3 is, for example, 10 g / m2 Hereinafter, preferably, 7 g / m 2 Hereinafter, more preferably, 5 g / m 2 or less.

[0168] Also, in the laminate 1, the polyurethane layer 3 may be an overcoat layer,

[0169] or an anchor coat layer. When the polyurethane layer 3 is an overcoat layer, the polyurethane layer 3 is the outermost layer in the laminate 1.

[0170] Also, when the polyurethane layer 3 is an anchor coat layer, the polyurethane layer 3 is an intermediate layer in the laminate 1. In such a case, the laminate 1 can further include a vapor deposition layer (not shown) laminated on the polyurethane layer 3. The vapor deposition layer is laminated on the polyurethane layer 3 by a known vapor deposition method.

[0171] Also, the total thickness of the laminate 1 is, for example, 5 μm or more, preferably 10 μm or more. Also, the total thickness of the laminate 1 is, for example, 1 mm or less, preferably 0.5 mm or less.

[0172] Such a laminate 1 includes the polyurethane layer 3 obtained using the above gas barrier coating material. More specifically, the polyurethane layer 3 is a dried product of the above gas barrier coating material.

[0173] That is, in the above laminate 1, the polyurethane layer 3 contains a polyurethane resin, and in the polyurethane resin, the polyisocyanate component contains xylylene diisocyanate, and the chain extender contains a predetermined ratio of ethylenediamine. Therefore, the above laminate 1 is excellent in gas barrier properties and heat resistance. Furthermore, if the polyurethane layer 3 contains a curing agent, the above laminate 1 is also excellent in moisture and heat resistance (retort resistance).

[0174] Therefore, the laminate 1 has excellent gas barrier properties and heat resistance. Therefore, the laminate 1 is suitably used in various industrial fields. Preferably, the laminate 1 is suitably used as a packaging material.

[0175] Examples of the packaging material include a food packaging film, a pharmaceutical packaging film, a food packaging container, an optical film, and an industrial film. In particular, since the laminate 1 has excellent heat resistance, it is suitably used as a food packaging film subjected to high-temperature sterilization treatment and a food packaging film subjected to heat cooking.

Examples

[0176] Next, the present invention will be described based on examples and comparative examples, but the present invention is not limited by the following examples. In addition, "parts" and "%" are based on mass unless otherwise specified. In addition, the specific numerical values such as the blending ratio (content ratio), physical property values, parameters, etc. used in the following description can be replaced with the upper limit values (numerical values defined as "hereinafter", "less than") or lower limit values (numerical values defined as "above", "exceeding") of the corresponding blending ratio (content ratio), physical property values, parameters, etc. described in the above "Mode for Carrying Out the Invention".

[0177] Synthesis Example 1 The following raw material components were reacted at 65 to 70 ° C. in a nitrogen atmosphere until the isocyanate group concentration (NCO%) became 9.53% by mass or less. Thereby, a reaction solution containing an isocyanate group-terminated prepolymer was obtained.

[0178] Raw material components 1,3-Xylylene diisocyanate (Takenate 500, 1,3-XDI, manufactured by Mitsui Chemicals, Inc.) 148.2 parts by mass Methylene bis(cyclohexyl isocyanate) (Vestanat H 12 MDI, H 12 MDI, manufactured by Evonik) 25.8 parts by mass Ethylene glycol 29.9 parts by mass Trimethylolpropane 2.3 parts by mass Dimethylolpropionic acid 17.0 parts by mass Methyl ethyl ketone (solvent) 126.9 parts by mass

[0179] Next, the reaction solution was cooled to 40°C. Then, 12.6 parts by mass of triethylamine was added to the reaction solution to neutralize the isocyanate group-terminated prepolymer. Next, the reaction solution was dispersed in 1000.0 parts by mass of ion-exchanged water by homodispersion. Then, an aqueous amine solution was added to the obtained dispersion to cause a chain extension reaction, and thereafter, it was aged for 1 hour. The aqueous amine solution was a mixed solution of 50.0 parts by mass of ion-exchanged water and 14.3 parts by mass of ethylenediamine. Thereafter, methyl ethyl ketone and ion-exchanged water were distilled off using an evaporator. Thereby, the solid content concentration was adjusted to 30% by mass. Thereby, a polyurethane dispersion (PUD) containing a gas barrier polyurethane resin was obtained.

[0180] Note that the molar ratio of the trivalent or higher alcohol (trimethylolpropane) in the active hydrogen group-containing component was calculated by a known method based on the hydroxyl equivalent (molecular weight / hydroxyl number) and the blending amount. More specifically, the ratio of trimethylolpropane to the active hydrogen group-containing component was 4.0 mol% as shown in the following formula. (2.3 parts by mass / 44.725) / [(29.9 parts by mass / 31.034) + (2.3 parts by mass / 44.725) + (17.0 parts by mass / 67.066)] × 100 = 4.0 mol% Hydroxyl equivalent of ethylene glycol: 31.034 Hydroxyl equivalent of trimethylolpropane: 44.725 Hydroxyl equivalent of dimethylolpropionic acid: 67.066

[0181] Synthesis Examples 2 to 18 According to the formulations described in Tables 1 to 2, a polyurethane dispersion was obtained in the same manner as in Synthesis Example 1.

[0182] Examples 1 to 7, 9 to 10, Comparative Examples 1 to 10, and 15 to 17 Using the formulations described in Tables 3 to 4, a polyurethane dispersion, a solvent (isopropanol), and ion-exchanged water were mixed. Thereby, a gas barrier coating material was obtained.

[0183] <Evaluation> (1) Storage stability (thermal stability) The viscosity at 25°C of the polyurethane dispersion of each synthesis example was measured under the following conditions. Apparatus: RB-85L manufactured by Toki Sangyo Co., Ltd. Rotation speed: 12 rpm, 30 rpm, 60 rpm Rotor number: No. 1 Next, the polyurethane dispersion was stored at 40°C for 14 days. Thereafter, the viscosity at 25°C of the polyurethane dispersion was measured under the above conditions. Then, the viscosity increase rate was determined by the following formula.

[0184] Viscosity increase rate (%) = viscosity after storage × 100 / viscosity before storage

[0185] (2) Coefficient of thermal expansion The polyurethane dispersion of each synthesis example was placed in a plastic tray and dried for 1 day under the conditions of 25°C and a relative humidity of 55%. Thereafter, it was heated at 110°C for 1 hour. Thereby, a film (thickness 200 μm) of the polyurethane resin was obtained. Next, the obtained film was cut into a length of 20 mm × a width of 5 mm. Thereby, a sample was obtained. Thereafter, using a thermomechanical analyzer (TMA-50 manufactured by SHIMADZU Corporation), the coefficient of thermal expansion of the sample was measured. The measurement conditions were set to a nitrogen atmosphere (gas flow rate 40 mL / min), a load setting of 0 g, and a heating rate of 10°C / min. The measurement was in accordance with JIS K7197 (1991).

[0186] Also, based on Examples 1, 5 to 7, Comparative Examples 2 and 4 to 6, the relationship between the coefficient of thermal expansion and the ratio of trimethylolpropane to the total amount of the active hydrogen group-containing component (TMP ratio) is shown in Figure 2.

[0187] That is, the chain extender of each example contains ethylenediamine. Therefore, when the active hydrogen group-containing component contains trimethylolpropane, the degree of improvement in heat resistance is particularly large. On the other hand, the chain extender of each comparative example does not contain ethylenediamine. Therefore, when the active hydrogen group-containing component contains trimethylolpropane, the degree of improvement in heat resistance is small.

[0188] Also, based on Examples 1, 9 to 10, Comparative Examples 2, 7 to 10, and 15 to 17, the relationship between the coefficient of thermal expansion and the ratio of methylene bis(cyclohexyl isocyanate) to the total amount of the polyisocyanate component (H 12 MDI ratio) is shown in FIG. 3.

[0189] That is, the chain extender of each example contains ethylenediamine. Therefore, when the polyisocyanate component contains methylene bis(cyclohexyl isocyanate), the degree of improvement in heat resistance is particularly large. On the other hand, the chain extender of each comparative example does not contain ethylenediamine. Therefore, when the polyisocyanate component contains methylene bis(cyclohexyl isocyanate), the degree of improvement in heat resistance is small.

[0190] (3) Gas barrier property (substrate: polyethylene terephthalate film) As the substrate, a polyethylene terephthalate film was prepared. The polyethylene terephthalate film is a biaxially stretched polyester film (trade name: Toyobo Estar Film E5102, manufactured by Toyobo Co., Ltd., thickness 12 μm).

[0191] Next, a gas barrier coating material was applied to the substrate using a bar coater. The coating amount was 1 g / m in terms of dry thickness 2 as.

[0192] Next, the film coated with the gas barrier coating material was placed in a drying oven set at 110°C for 1 minute to be dried. Thereby, a laminate including a base material and a polyurethane layer was obtained. Then, using an oxygen permeability measuring device (MOCON, OX-TRAN2 / 20), the oxygen permeability of the laminate was measured. The measurement conditions were set at 20°C and a relative humidity of 70% (70% RH). The measurement was in accordance with JIS K7126-2 (2006). Also, 1 m 2 , the oxygen permeation amount (cc / m 2 ·day·atm) per day and per atmospheric pressure was measured.

[0193] [Table 1]

[0194] [Table 2]

[0195] [Table 3]

[0196] [Table 4]

[0197] Example 13 According to the formulation described in Table 5, a polyurethane dispersion, an isocyanate curing agent (Takenate WD-725, manufactured by Mitsui Chemicals), a solvent (isopropanol), and ion-exchanged water were mixed. Thereby, a gas barrier coating material was obtained.

[0198] (4) Gas barrier property (base material: polypropylene film) As the base material, a polypropylene film was prepared. The polypropylene film is an unstretched polypropylene film (Tosero CP RXC-22 (CPP film), #60, manufactured by Mitsui Chemicals Tohcello, Inc.).

[0199] Next, a gas barrier coating material was applied to the base material using a bar coater. The coating amount was a thickness of 3 g / m when dry. 2 Next, the film coated with the gas barrier coating material was placed in a drying oven set at 80°C for 1 minute to be dried. Then, it was heated at 40°C for 2 days. Thereby, a laminate including the base material and the polyurethane layer was obtained. Then, the oxygen transmission rate was measured in the same manner as in Example 1.

[0200] Example 14 With the formulation described in Table 5, a polyurethane dispersion, an isocyanate curing agent (Takenate WD-725, manufactured by Mitsui Chemicals), a solvent (isopropanol), ion-exchanged water, and a leveling agent (BYK-348, manufactured by BYK) were mixed. Thereby, a gas barrier coating material was obtained.

[0201] (5) Gas barrier property (base material: polyethylene film) As the base material, a polyethylene film was prepared. The polyethylene film is a low-density polyethylene film (LLDPE film, manufactured by Mitsui Chemicals Tohcellulose Co., Ltd., TUXHC, thickness 60 μm). Next, a gas barrier coating material was applied to the base material using a bar coater. The coating amount was a thickness of 3 g / m when dry. 2 was used.

[0202] Next, the film coated with the gas barrier coating material was placed in a drying oven set at 80°C for 1 minute to be dried. Then, it was heated at 40°C for 2 days. Thereby, a laminate including the base material and the polyurethane layer was obtained. Then, the oxygen transmission rate was measured in the same manner as in Example 1.

[0203] Example 15 With the formulation described in Table 5, a polyurethane dispersion, an isocyanate curing agent (Takenate WD-725, manufactured by Mitsui Chemicals), a solvent (isopropanol), and ion-exchanged water were mixed. Thereby, a gas barrier coating material was obtained.

[0204] (6) Gas barrier property (substrate: polypropylene film) As the substrate, a polypropylene film was prepared. The polypropylene film is an unstretched polypropylene film (Tosello CP RXC-22 (CPP film), #60, manufactured by Mitsui Chemicals Tohcello, Inc.). Next, a gas barrier coating material was applied to the substrate using a bar coater. The coating amount was 0.5 g / m in terms of dry thickness 2 was set.

[0205] Next, the film coated with the gas barrier coating material was placed in a drying oven set at 80 °C for 1 minute to dry. Then, it was heated at 40 °C for 2 days. Next, after being mounted on a vacuum aluminum evaporation machine (Showa Vacuum, SIP600), aluminum was installed as the evaporation source, and then the degree of vacuum in the evaporation chamber was set to 2×10 -3 mbar. Then, the current value was gradually increased to dissolve aluminum at 700 mA, and aluminum was evaporated with a total evaporation time of 3 seconds. Thus, a laminate including a substrate, a polyurethane layer, and an evaporated layer was obtained. Thereafter, the oxygen transmission rate was measured in the same manner as in Example 1.

[0206] Example 16 With the formulation described in Table 5, a polyurethane dispersion, an isocyanate curing agent (Takenate WD-725, manufactured by Mitsui Chemicals), a solvent (isopropanol), ion-exchanged water, and a leveling agent (BYK-348, manufactured by BYK) were mixed. Thus, a gas barrier coating material was obtained.

[0207] (7) Gas barrier property (substrate: polyethylene film) A laminate including a substrate, a polyurethane layer, and an evaporated layer was obtained in the same manner as in Example 15, except that a low-density polyethylene film (LLDPE film, manufactured by Mitsui Chemicals Tohcello, Inc., TUXHC, thickness 60 μm) was used instead of the unstretched polypropylene film. Thereafter, the oxygen transmission rate was measured in the same manner as in Example 1.

[0208] Example 17 Using the formulation described in Table 5, a polyurethane dispersion, an isocyanate curing agent (Takenate WD-725, manufactured by Mitsui Chemicals), a solvent (isopropanol), and ion-exchanged water were mixed. As a result, a gas barrier coating material was obtained.

[0209] (8) Gas barrier property (substrate: polypropylene film) As the substrate, a polypropylene film was prepared. The polypropylene film was an unstretched polypropylene film (Toselo CP RXC-22 (CPP film), #100, manufactured by Mitsui Chemicals Tohcello Co., Ltd.). Next, the gas barrier coating material was applied to the substrate using a bar coater. The coating amount was 0.5 g / m in terms of dry thickness. 2 was set.

[0210] Next, the film coated with the gas barrier coating material was placed in a drying oven set at 80°C for 1 minute to be dried. Then, it was heated at 40°C for 2 days. Next, after heating for 1 minute at a preheating temperature of 158°C using a batch stretching machine, it was stretched 6 times in the flow direction of the film.

[0211] Next, after mounting on a vacuum aluminum evaporation machine (Showa Vacuum, SIP600), aluminum was installed as the evaporation source, and then the degree of vacuum in the evaporation chamber was set to 2×10 -3 mbar.

[0212] Thereafter, the current value was gradually increased to dissolve aluminum at 700 mA, and aluminum was evaporated with a total evaporation time of 3 seconds. As a result, a laminate including a substrate, a polyurethane layer, and an evaporated layer was obtained. Thereafter, the oxygen transmission rate was measured in the same manner as in Example 1.

[0213] Example 18 Using the formulation described in Table 5, ion-exchanged water, a polyurethane dispersion, a thickener (Primal RM-8W, manufactured by The Dow Chemical Company, solid content concentration 21.5%), and a swellable layered inorganic compound (NTS-5, manufactured by Toppan Industries, solid content concentration 6%) were blended and mixed with a mixer. As a result, a gas barrier coating material was obtained.

[0214] (9) Gas barrier property (substrate: paper) On the coated surface of coated paper (N - coat trap L, made by Nippon Paper Industries Co., Ltd., basis weight 65 g / m 2 ), the above gas barrier coating material was applied with a bar coater, and the coating film was dried at 120°C for 90 seconds. Next, the above gas barrier coating material was further applied with a bar coater, and the coating film was dried at 120°C for 90 seconds. Then, it was cured for 2 days under the conditions of 23°C and 50% RH. Thereby, a polyurethane layer was formed on one surface of the paper substrate to obtain a laminate. The coating amount was 6.0 g / m in terms of dry thickness 2 . Thereafter, the oxygen transmission rate was measured in the same manner as in Example 1.

[0215] Example 19 According to the formulation described in Table 5, water, a polyurethane dispersion, a thickener (Primer RM - 8W, made by Dow Chemical Company, solid content concentration 21.5%), and a swellable layered inorganic compound (ME300 - B4T, made by Katakura Copa Agri Co., Ltd., solid content concentration 8%) were blended and mixed with a mixer. Thereby, a gas barrier coating material was obtained.

[0216] (10) Gas barrier property (substrate: paper) On the coated surface of coated paper (N - coat trap L, made by Nippon Paper Industries Co., Ltd., basis weight 65 g / m 2 ), the above gas barrier coating material was applied with a bar coater, and the coating film was dried at 120°C for 90 seconds. Next, the above gas barrier coating material was further applied with a bar coater, and the coating film was dried at 120°C for 90 seconds. Then, it was cured for 2 days under the conditions of 23°C and 50% RH. Thereby, a polyurethane layer was formed on one surface of the paper substrate to obtain a laminate. The coating amount was 6.0 g / m in terms of dry thickness 2 . Thereafter, the oxygen transmission rate was measured in the same manner as in Example 1.

[0217] Example 20 Using the formulation described in Table 5, ion-exchanged water, a polyurethane dispersion, and a swelling layered inorganic compound (NTS-5, manufactured by Toppan Industries, solid content concentration 6%) were blended and mixed with a mixer. Thereby, a gas barrier coating material was obtained.

[0218] (11) Gas barrier property (substrate: paper) On the coated surface of coated paper (N Coatrap L, manufactured by Nippon Paper Industries, basis weight 65 g / m 2 ), as an anchor coating material, OJb-51 (an aqueous dispersion of an aqueous acrylic resin, solid content 25%) was applied with a bar coater and dried at 120°C for 90 seconds. The coating amount of the anchor coating material was 2.0 g / m in terms of dry thickness. 2 was used.

[0219] Next, the above gas barrier coating material was applied with a bar coater, and the coating film was dried at 120°C for 90 seconds. The coating amount of the gas barrier coating material was 2.5 g / m in terms of dry thickness. 2 was used. Then, it was cured for 2 days under the conditions of 23°C and 50% RH. Thereby, a polyurethane layer was formed on one side of the paper substrate, and a laminate was obtained. Then, the oxygen permeability was measured in the same manner as in Example 1.

[0220] Example 21 Using the formulation described in Table 5, a polyurethane dispersion, a solvent (isopropanol), an epoxy silane (KBM-403, manufactured by Shin-Etsu Chemical), and ion-exchanged water were mixed. Thereby, a gas barrier coating material was obtained.

[0221] (12) Gas barrier property (substrate: aluminum oxide vapor-deposited polyethylene terephthalate) As a substrate, aluminum oxide vapor-deposited polyethylene terephthalate (Barrierox 1011HG (#12), manufactured by Toray Film Processing Co., Ltd.) was prepared. Next, the gas barrier coating material was applied to the substrate using a bar coater. The coating amount was 0.5 g / m in terms of dry thickness. 2 was used.

[0222] Next, the film coated with the gas barrier coating material was placed in a drying oven set at 110°C for 1 minute to be dried. Then, it was heated at 50°C for 2 days. Thereby, a laminate including a base material and a polyurethane layer was obtained. Then, the oxygen transmission rate was measured in the same manner as in Example 1.

[0223] Examples 22 to 32 and Comparative Examples 11 to 14 With the formulations described in Tables 6 to 7, a polyurethane dispersion, a solvent (isopropanol), ion-exchanged water, and a curing agent were mixed. Thereby, a gas barrier coating material was obtained.

[0224] (13) Gas barrier property and retort resistance In Examples 22 to 28, 31 to 32 and Comparative Examples 11 to 13, an alumina-deposited polyethylene terephthalate film (alumina-deposited PET, TL-PET-H, manufactured by Mitsui Chemicals Toagosei Co., Ltd.) was prepared as the base material.

[0225] Also, in Examples 29 to 30 and Comparative Example 14, an alumina-deposited biaxially oriented polypropylene film (alumina-deposited OPP) was prepared as the base material. The alumina-deposited OPP is a laminated film in which aluminum oxide (Al2O3) is vapor-deposited (under a vacuum condition of 1×10 -4 Pa, RH method) on one side of a biaxially oriented polypropylene film (high heat-resistant Pyren film, thickness 20 μm, manufactured by Toyobo Co., Ltd.) to form a metal vapor-deposited layer with a thickness of 10 nm.

[0226] Next, the gas barrier coating material was applied to the alumina-deposited PET using a bar coater. The coating amount was 0.5 g / m in terms of dry thickness 2 . Next, the film coated with the gas barrier coating material was placed in a drying oven set at 110°C for 1 minute to be dried. Then, it was heated at 50°C for 2 days. Thereby, a laminate including a base material and a polyurethane layer was obtained.

[0227] Further, a gas barrier coating material was applied to the alumina vapor-deposited OPP using a bar coater. The coating amount was 0.5 g / m in terms of the thickness after drying. 2 Next, the film coated with the gas barrier coating material was placed in a drying oven set at 80°C for 1 minute to be dried. Then, it was heated at 50°C for 2 days. Thereby, a laminate including a base material and a polyurethane layer was obtained.

[0228] The oxygen permeability of the laminate was measured using an oxygen permeability measuring device (MOCON, OX-TRAN2 / 20). The measurement conditions were set at 20°C and a relative humidity of 70% (70% RH). Also, the measurement was in accordance with JIS K7126-2 (2006). Also, for 1 m², the oxygen transmission rate per day and per atmospheric pressure (cc / m²·day·atm) was measured. 2 、1 day and the oxygen transmission rate per atmospheric pressure (cc / m²·day·atm) was measured. 2 ·day·atm) was measured.

[0229] Next, the laminate was immersed in hot water at 120°C for 30 minutes for hot water treatment. Then, the oxygen permeability of the hot water-treated laminate was measured under the above conditions. And the increase rate of the oxygen permeability was obtained by the following formula. Note that the higher the value of the increase rate of the oxygen permeability, the lower the evaluation of the retort resistance. [(Oxygen permeability after hot water treatment - Oxygen permeability before hot water treatment) / Oxygen permeability before hot water treatment]

[0230] (14) Adhesion and retort resistance To the polyurethane layer of the laminate, a mixture of Tacklac A-310 (manufactured by Mitsui Chemicals, Inc.) and Takenate A-3 (manufactured by Mitsui Chemicals, Inc.) as an adhesive (Tacklac A-310 / Takenate A-3 = 10 / 1 (mass ratio)) was applied with a bar coater so as to have a dry thickness of 3.0 g / m² and dried with a dryer. 2 and dried with a dryer.

[0231] Next, an unstretched polypropylene film (Toselo CP RXC-22 (CPP film), #60, manufactured by Mitsui Chemicals Toagosei Co., Ltd.) was laminated on the coated surface of the adhesive and cured at 50°C for 3 days. Thereby, a laminated film was obtained.

[0232] The laminate strength of the laminate film was measured by a T-peel test (15 mm width) conforming to JIS K 6854 (1999). Further, the laminate film was immersed in hot water at 120°C for 30 minutes for heat treatment. Then, the laminate strength of the heat-treated laminate film was measured under the above conditions.

[0233] (15) Coefficient of thermal expansion Each gas barrier coating material was placed in a plastic tray and dried for 1 day under the conditions of 25°C and a relative humidity of 55%, and then heated at 110°C for 1 hour. Thereby, a film of polyurethane resin (thickness: 200 μm) was obtained. Next, the obtained film was cut into pieces of 20 mm in length and 5 mm in width. Thereby, samples were obtained. Then, using a thermomechanical analyzer (manufactured by SHIMADZU Corporation, TMA-50), the coefficient of thermal expansion of the samples was measured. The measurement conditions were set to a nitrogen atmosphere (gas flow rate: 40 mL / min), a load setting of 0 g, and a heating rate of 10°C / min. The measurement was conducted in accordance with JIS K7197 (1991).

[0234] [Table 5]

[0235] [Table 6]

[0236] [Table 7]

[0237] The details of the abbreviations in the table are described below. PUD: Polyurethane dispersion BYK-348: Product name BYK-348, leveling agent, manufactured by BYK NTS-5: Product name NTS-5, layered inorganic compound, manufactured by Toppy Industries, Ltd. ME300-B4T: Product name ME300-B4T, layered inorganic compound, manufactured by Katakura Chikkarin Co., Ltd. RM-8W: Product name: Primar RM-8W, thickener, manufactured by Dow Chemical CPP: Unstretched polypropylene film LLDPE: Low-density polyethylene film AlOxPET: Aluminum oxide vapor-deposited polyethylene terephthalate Over: Overcoat layer Anchor: Anchor coat layer KBM-403: Product name: KBM-403, epoxy silane, manufactured by Shin-Etsu Chemical WD-725: Product name: Takenate WD-725, water-dispersible polyisocyanate, manufactured by Mitsui Chemicals Bayhydur 3100: Product name: Bayhydur 3100, water-dispersible polyisocyanate, manufactured by BASF V-02: Carbodiimide compound, product name: Carbodilite V-02, solid content concentration 40% by mass, manufactured by Nisshinbo Chemical V-02-L2: Carbodiimide compound, product name: Carbodilite V-02-L2, solid content concentration 40% by mass, manufactured by Nisshinbo Chemical SV-02: Carbodiimide compound, product name: Carbodilite SV-02, solid content concentration 40% by mass, manufactured by Nisshinbo Chemical MF: Material fracture

Explanation of symbols

[0238] 1 Laminate 2 Substrate 3 Polyurethane layer

Claims

1. A polyurethane dispersion which is an aqueous dispersion of a polyurethane resin, wherein the polyurethane resin is a reaction product of an isocyanate group-terminated prepolymer and a chain extender, the isocyanate group-terminated prepolymer includes a reaction product of a polyisocyanate component containing xylylene diisocyanate, a short-chain diol having 2 to 6 carbon atoms, and an active hydrogen group-containing component including an active hydrogen group-containing compound containing a hydrophilic group, the hydrophilic group is a carboxy group, the chain extender includes ethylenediamine, the ratio of ethylenediamine to the total amount of the chain extender is 25 mol% or more, the polyisocyanate component further includes methylene bis(cyclohexyl isocyanate), the content ratio of methylene bis(cyclohexyl isocyanate) to the total amount of the polyisocyanate component is 1 mol% or more and 30 mol% or less, A polyurethane dispersion characterized by the above.

2. the active hydrogen group-containing component further includes an alcohol having 3 or more valences, the ratio of the alcohol having 3 or more valences to the total amount of the active hydrogen group-containing component is 1 mol% or more and 15 mol% or less, The polyurethane dispersion according to claim 1, characterized by the above.

3. The coefficient of thermal expansion of the polyurethane resin is 2000×10 －６ K －１ or less The polyurethane dispersion according to claim 1, characterized by the above.

4. Furthermore, the polyurethane dispersion according to claim 1, including at least one selected from the group consisting of an epoxy silane, an aqueous dispersion isocyanate, and a carbodiimide compound.

5. The content ratio of the carbodiimide group in the carbodiimide compound is, 0.3 mol or more and 3.0 mol or less with respect to 1 mol of the carboxy group in the polyurethane resin. The polyurethane dispersion according to claim 4.

6. Including the polyurethane dispersion according to claim 1, A gas barrier coating material characterized by the above.

7. Comprising a substrate and a polyurethane layer disposed on the surface of the substrate, A laminate, characterized in that the polyurethane layer is a dried product of the gas barrier coating material according to claim 6.

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